115. Prosthetic Valve Endocarditis (PVE) Caused by Bartonella henselae: A Case Report of Molecular Methods to Diagnose and Inform Non-surgical Management
Session: Oral Abstract Session: Coming Soon to a Bloodstream Near You
Thursday, October 27, 2016: 10:45 AM
Room: 275-277

Background:  Culture-negative endocarditis caused by Bartonella henselae is often difficult to diagnose.  We report a patient in whom molecular testing on whole blood permitted rapid pathogen identification and subsequent medical management of B. henselae aortic PVE and graft infection.

A 58-year old man with Ehlers-Danlos syndrome presented with 7 weeks of fevers, drenching night sweats and an 8-pound weight loss.  His past medical history was notable for an aortic graft, mechanical aortic valve and a mitral anulloplasty ring placed 10 years before presentation.  He lived with a monkey and 15 cats on an organic farm where he walked barefoot while plowing soil.  He previously kept goats.  Blood cultures obtained before starting antibiotics were negative for pathogens.  A trans-esophogeal echocardiogram did not reveal any valvular lesions or vegetationsFigure 1 shows an 18fluorodeoxyglucose-positron emission tomography/computed tomography (18FDG-PET/CT) scan that detected abnormal hypermetabolic activity in the aortic arch (A), aortic root/valve prosthesis (B), spleen (C) and axillary region of the right subclavian artery (D). 

Methods:   Nucleic acid testing using research based PCR/electrospray ionization mass spectrometry (PCR/ESI-MS) and sequencing targeting 16S rRNA genes was performed on whole blood.  Western blots (WB) tested serum for antibodies against Bartonella spp.

Results:  PCR/ESI-MS detected Bartonella henselae from blood samples collected on hospital days 2 and 3.  WB yielded a reactivity pattern consistent with Bartonella henselae infection.  The patient received 4 weeks of gentamicin concurrent with 8 weeks of ceftriaxone.  His symptoms improved within 6 days of starting antibiotics.  He remains asymptomatic while on daily doxycycline for suppression.

Conclusion:  PCR/ESI-MS applied to whole blood permitted rapid detection of B. henselae, which was confirmed by 16S sequencing.  Together with the WB findings and clinical picture, prompt initiation of targeted antimicrobial therapy for culture-negative graft and aortic PVE infection is proving to be very useful.  PCR/ESI-MS is defining its role in detecting pathogens in culture-negative infections and reducing the need for surgical management of PVE.

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Patricia Bartley, MD, Case Western Reserve University School of Medicine, Cleveland, OH, Emmanouil Angelakis, MD, PhD, Unite De Recherche Sur Les Maladies Infectieuses Et Tropicales Emergentes (URMITE), Aix-Marseille Université, Marseille, France, Didier Raoult, MD, PhD, Faculte' de Medecine, Marseille, FRANCE, Rangarajan Sampath, PhD, Ibis Biosciences, Inc., Carlsbad, CA, Robert A. Bonomo, MD, Pharmacology, Molecular Biology, and Microbiology, Case Western Reserve University, Cleveland, OH; Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland, OH and Robin Jump, MD, PhD, Division of Infectious Diseases and HIV Medicine, Case Western Reserve University, Cleveland, OH; Geriatric Research Education and Clinical Center (GRECC), Louis Stokes Cleveland Department of Veterans Affairs Medical Center, Cleveland, OH

Disclosures:

P. Bartley, None

E. Angelakis, None

D. Raoult, None

R. Sampath, Ibis Biosciences, Abbott: Employee , Salary

R. A. Bonomo, Merck: Grant Investigator , Grant recipient
Allergan: Grant Investigator , Grant recipient
Wockhardt: Grant Investigator , Grant recipient

R. Jump, Pfizer: Grant Investigator , Grant recipient

Findings in the abstracts are embargoed until 12:01 a.m. CDT, Wednesday Oct. 26th with the exception of research findings presented at the IDWeek press conferences.